How Rangefinders Work
There are many different brands and styles of laser rangefinders from which you can select. They’re manufactured by Opti-Logic, LaserTechnology, Newcon Optik, Nikon and Bushnell, just to name a few. As there are naturally many choices, you first need to know how an electronic rangefinder works to help you select the best one for your needs.

Dual Purpose Rangefinders:
These all around rangefinders see use during both archery and rifle season. The are generally capable of ranging targets at several hundred yards, and often have features that are favored by both rifle and bow hunters, such a target priority modes and a scan mode. Many of these units also have both a "bow" and "rifle" mode which allows the user to select which mode best fits their current hunting situation.

Range
The distances at which rangefinders can effectively calculate distances can vary from 100 meters to up to 25 kilometers, and quite possibly much further if the investment warrants it. Generally the super long distance rangefinders are built for military purposes and used by snipers and artillery units.